This invention relates to tree cutting equipment, and more particularly to an apparatus for extracting a portion of a tree stump from the ground after the main trunk portion or stem of the tree has been removed.
Trees, such as various species of pine, that are grown for industrial purposes including lumber and pulp, are usually cut after a predetermined growth cycle of 20 to 30 years, for example. Some time prior to harvesting of the pine tree a chemical additive can be injected or otherwise furnished to the tree to facilitate the removal operation.
Generally the trunk or stem of the tree is cut a predetermined height from the ground leaving behind the root of the tree and a tree stump of predetermined size. The root of the pine tree includes a tap root portion which extends directly into the ground and a lateral root portion with root branches that extend laterally away from the trunk in all directions.
It is well known that a pine tree contains oleoresin, a crude gum from which turpentine and rosin, also known as naval stores, are derived. The oleoresin has its greatest concentration in the stump of the tree at a section known as the watermelon portion. The watermelon portion is the section of the stump that extends from the point at which the tree has been sheared down to the ground level, but does not include the lateral root portion or the tap root portion.
Generally the watermelon portion is approximately 30 inches in length, whereas the tap root extends approximately 5 feet into the ground and the lateral root, although shallower than the tap root has a relatively broad swath.
In order to extract the oleoresin from the stump it is customary to remove the stump from the ground for chopping or grinding into chips and eventually shreds that are of matchstick size. The shreds are then further processed to extract the oleoresin.
Although the roots of the stump are not desired for the extraction of oleoresin it is common practice to harvest the stump by pulling it out of the ground with the entire root. Consequently a large amount of earth is brought up during the stump removal operation resulting in the formation of an unsightly and environmentally undesirable cavity at the site of the removed stump. Such cavity must be filled in or the ground otherwise restored to a condition suitable for tree replanting. The ground restoration operation is tedious, messy and time consuming, and also significantly adds to the cost of the stump removal.
Because the root of the tree creates more problems out of the ground than in the ground it would be beneficial to remove the watermelon portion of the tree stump without removing the root. However thus far there is no known apparatus which will feasibly remove only the watermelon portion of the tree stump from the ground while leaving the root behind.
It is thus desirable to provide an apparatus for extracting the watermelon portion of a tree stump from the ground without removing the root.
Unless otherwise indicated the term tree stump as hereinafter used is intended to refer to the watermelon portion of the tree stump.